Effect of cystine loading and cystine dimethylester on renal brushborder membrane transport.
The effect of loading renal tubule cells with cystine was studied by incubating them with cystine dimethylester. Proline uptake into brushborder membrane vesicles isolated from the cystine loaded cells was not different from that observed into brushborder vesicles isolated from tubules incubated in buffer alone. Incubating brushborder membranes with 2 mM cystine dimethylester for 10 minutes reduced the uptake of proline by 27% after 15 seconds of incubation and by 21% after 60 seconds of incubation. There was no effect after 20 minutes of incubation. Pre-incubating brushborder membrane vesicles with cystine dimethylester had no statistically significant effect on the affinity of proline for the carrier, but did reduce the maximal rate of proline uptake by 49%.
Foreman
J W
JW
Department of Pediatrics, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298.
Benson
L
L
D000818:Animals; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D003553:Cystine / Q000031:analogs & derivatives* / Q000494:pharmacology; D003554:Cystinosis / Q000503:physiopathology; D005198:Fanconi Syndrome / Q000209:etiology; D007684:Kidney Tubules / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008871:Microvilli / Q000187:drug effects / Q000378:metabolism*; D011392:Proline / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D003553:Cystine; D011392:Proline; C034582:cystine dimethyl ester